<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<script>

    let secondsInMinute = 60;
    let minutesInHour = 60;

    let secondsInHour = secondsInMinute * minutesInHour;

    console.log("Секунд в часе " + secondsInHour);
</script>
</body>
</html>